Single tenant SIP (Session Initiation Protocol) server solutions, i.e., with only one SIP server instance being provided per tenant or company, are implemented in cloud infrastructures by means of virtualization technologies more and more. In such a single tenant constellation, the tenant may grow or shrink substantially, for example, because the number of users increases or decreases drastically, and, in order to optimize server resources, it may become necessary to move the single tenant SIP server software application by means of virtualization technologies (e.g., vMotion or the like) to another physical server which has higher capacities available.
However, with respect to multi-tenancy SIP server solutions in which one SIP server instance is configured to host a plurality of tenants rather than only one tenant, the scenario described above is rather difficult especially regarding cloud infrastructures for the reasons outlined below.
Moreover, tenants which may be regarded as an operational unit providing services to users of a customer consuming services may have different sizes, for example, ranging from 10 users to e.g. 400,000 users, which have to be supported. Also here, the tenant sizes may vary substantially over time and may also be regarded as a dynamically changing factor such that, as already has been noted with respect to single tenant SIP server solutions, problems with respect to server resources may occur.
If, for example, a company as an example for a tenant, grows and the number of users thus increases substantially so that resources of the SIP server instance on which this tenant resides are becoming scarce, it may be necessary to move tenants from one SIP server instance (for example, a first virtual machine) to another SIP server instance (for example, a second virtual machine) in order to enable optimal utilization of the physical server resources thereby allowing economical operation of such a cloud solution. However, in prior art it is known to move complete virtual machines (i.e., the entire SIP server instances with all tenants configured thereon) between servers which will not be sufficient for achieving the above mentioned aim of optimal utilization of server resources.
Load balancing solutions known in prior art are all rather complex and involve manual and thus expensive management intervention in order to move tenants of a multi-tenant SIP (e.g. VOIP—Voice over Internet Protocol) server system to another SIP server. Therefore, the present invention is based on the object to provide a computer-implemented method for managing more efficiently tenants on a multi-tenant SIP server system in cloud environments.